A known flat screen printing machine (Otdelka i Krashenie sherstyannyh tkanei. Handbook edited by V. L. Molokov. Moscow, Legprombytizdat, 1985, 264 p.) which has two flat doctors comprises an endless rubberized conveyor, a flat screen, a doctor unit and a frame. The flat screen is fastened rigidly to the frame, and the doctors are disposed laterally to the endless rubberized conveyor. To the frame there is mounted the doctor unit. This doctor unit consists of two pairs of mechanisms for two-sided attachment of both flat doctors and for regulating their angle and pressure on the flat screen.
A drawback of the flat doctors lies in that they cannot be used with foamed printing pastes, since the foamed paste, analogous to the ordinary paste, is in free state between the doctors on the screen where, as a result of the continuous mechanical action of both flat doctors, the paste is further foamed or broken down. This results in a change of the properties of the foam and in an abrupt worsening of the print. Another drawback is that the feeding with printing paste is manual, and can detrimentally affect worker hygiene. There appear frequently faults on the textile materials because of the spread of paste over their surface, particularly in the printing of blankets with low-viscosity printing pastes. Because of the poor penetration of the paste in the printing of bulky cloth, a repeated doctoring is necessary and can in a reduction of the output of the machine.